pH-Corrected Ionised Calcium Predicts Coagulopathy After Major Trauma: A Retrospective Cohort Study

Area of Science:

• Trauma research
• Clinical chemistry
• Critical care medicine

Background:

• Ionized calcium (iCa2+) plays a crucial role in trauma pathophysiology, affecting coagulation and hemodynamics.
• Acidaemia and hypocalcaemia are common in major trauma and influence iCa2+ levels.
• Accurate and timely assessment of iCa2+ is vital for patient management.

Purpose of the Study:

• To evaluate the prognostic utility of pH-corrected ionized calcium (ciCa2+) from blood gas analyzers in major trauma.
• To compare the predictive performance of ciCa2+ against standard ionized calcium (iCa2+) for mortality, coagulopathy, and transfusion requirements.

Main Methods:

• Retrospective cohort study of major trauma patients (Injury Severity Score ≥ 13) aged ≥ 16 years.
• Exclusion criteria included missing data, pre-measurement blood product administration.
• Logistic regression and ROC curve analysis were used to compare ciCa2+ and iCa2+ prognostic performance.

Main Results:

• ciCa2+ ≤ 1.1 mmol/L was not initially associated with mortality but became independently associated after adjusting for age and ISS.
• ciCa2+ demonstrated strong associations with coagulopathy (OR 23.0) and transfusion (OR 2.54).
• ciCa2+ showed superior discrimination for coagulopathy (AUROC 0.95) and transfusion (AUROC 0.69) compared to iCa2+ (0.56 and 0.54, respectively).

Conclusions:

• pH-corrected ionized calcium (ciCa2+) is a valuable prognostic marker in major trauma.
• ciCa2+ effectively incorporates the effects of acidaemia and hypocalcaemia, offering a practical risk stratification tool.
• ciCa2+ outperforms uncorrected iCa2+ in predicting key trauma outcomes.